The present invention is directed to a fail-safe release mechanism, apparatus or device, for use with patient positioning support apparati, or surgical tables, that include at least one elongate patient support structure, frame or imaging table top removably connected or joined at both ends thereof to upright end supports of a base structure by spaced opposed connection subassemblies. Exemplary patient support structures, for use with the present invention, may include a pair of spaced opposed hinges or joints, so as to be angulatable, or articulatable. Such hinges can be actively driven or passively moved. The exemplary patient support structures may also have a length adjustment feature, such as a telescoping mechanism, a translator connector, a slider bar or some other type of translation compensation mechanism. It is foreseen that this length adjustment mechanism or structure could be part of or incorporated within one or both connection subassemblies. It could also be within the base itself, in the form of a telescoping parts, bearing blocks or other appropriate structure.